Dart Macros: Metaprogramming Revolutionized

[!TIP] Use macros to automate JSON serialization, data class generation, and more without build_runner.

Introduction

Dart macros represent a significant leap forward for the language, introducing a powerful system for static metaprogramming. Unlike traditional code generation which relies on external tools like build_runner, macros run directly as part of the compilation process.

Key Benefits

1. No more build_runner: Macros run instantly as you type or compile.
2. Cleaner Codebase: Generated code is managed by the compiler, keeping your source tree clean.
3. Powerful Introspection: Inspect and modify code structure at compile time.

Example: JSON Serialization

With the new JsonCodable macro, implementing toJson and fromJson becomes trivial:

@JsonCodable()
class User {
  final String name;
  final int age;
}

This single annotation automatically generates the necessary serialization logic, invisible to the user but fully type-safe.

The Road Ahead

Macros are currently in preview and expected to stabilize in upcoming Dart releases. They pave the way for a more efficient and developer-friendly ecosystem.